Posted
by
timothyon Tuesday December 04, 2012 @01:00PM
from the pilgrims'-progress dept.

MrSeb writes "In its continuing mission to build a 'Wiki Weapon,' Defense Distributed has 3D printed the lower receiver of an AR-15 and tested it to failure. The printed part only survives the firing of six shots, but for a first attempt that's quite impressive. And hey, it's a plastic gun. Slashdot first covered 3D-printed guns back in July. The Defense Distributed group sprung up soon after, with the purpose of creating an open-source gun — a Wiki Weapon — that can be downloaded from the internet and printed out. The Defense Distributed manifesto mainly quotes a bunch of historical figures who supported the right to bear arms. DefDist (its nickname) is seeking a gun manufacturing license from the ATF, but so far the feds haven't responded. Unperturbed, DefDist started down the road by renting an advanced 3D printing machine from Stratasys — but when the company found out what its machine was being used for, it was repossessed. DefDist has now obtained a 3D printer from Objet, which seemingly has a more libertarian mindset. The group then downloaded HaveBlue's original AR-15 lower receiver from Thingiverse, printed it out on the Objet printer using ABS-like Digital Material, screwed it into an AR-57 upper receiver, loaded up some FN 5.7x28mm ammo, and headed to the range. The DefDist team will now make various modifications to HaveBlue's design, such as making it more rugged and improving the trigger guard, and then upload the new design to Thingiverse." Sensible ammo choice; 5.7x28mm produces less recoil than the AR-15's conventional 5.56mm. I wonder how many of the upper's components, too, can one day be readily replaced with home-printable parts — for AR-15 style rifles, the upper assembly is where the gun's barrel lives, while the lower assembly (the part printed and tested here) is the legally controlled part of the firearm.

In gun safety they show you what even an obstructed barrel can result in when firing a gun.

Yes, but I'm having a harder time imagining what a defect in the lower receiver would cause that would be equivalent to firing a bullet into an obstructed barrel.

That's the car equivalent of 3D printing a new hood and then saying man that's crazy risky -- just look at the damage that can happen when the brakes fail.

The obstruction example was not meant to be an example of what could go wrong here, just how easily guns can become tiny explosions in your face. For your car example, the hood can fly up into your field of view when you take it out on the highway and you could crash into anything. The lower receiver could crumble apart and cause any number of issues for the person holding it including loss of control of the direction of the bullet.